Featured Research

from universities, journals, and other organizations

NASA's Deep Impact spacecraft eyes comet ISON

Date:

February 5, 2013

Source:

NASA/Jet Propulsion Laboratory

Summary:

NASA's Deep Impact spacecraft has acquired its first images of comet C/2012 S1 (ISON). The images were taken by the spacecraft's Medium-Resolution Imager over a 36-hour period on Jan. 17 and 18, 2013, from a distance of 493 million miles (793 million kilometers). Many scientists anticipate a bright future for comet ISON; the spaceborne conglomeration of dust and ice may put on quite a show as it passes through the inner solar system this fall.

Share This

This is the orbital trajectory of comet C/2012 S1 (ISON). The comet is currently located just inside the orbit of Jupiter. In November 2013, ISON will pass less than 1.1 million miles (1.8 million kilometers) from the sun's surface. The fierce heating it experiences during this close approach to the sun could turn the comet into a bright naked-eye object.

NASA's Deep Impact spacecraft has acquired its first images of comet C/2012 S1 (ISON). The images were taken by the spacecraft's Medium-Resolution Imager over a 36-hour period on Jan. 17 and 18, 2013, from a distance of 493 million miles (793 million kilometers). Many scientists anticipate a bright future for comet ISON; the spaceborne conglomeration of dust and ice may put on quite a show as it passes through the inner solar system this fall.

Related Articles

"This is the fourth comet on which we have performed science observations and the farthest point from Earth from which we've tried to transmit data on a comet," said Tim Larson, project manager for the Deep Impact spacecraft at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The distance limits our bandwidth, so it's a little like communicating through a modem after being used to DSL. But we're going to coordinate our science collection and playback so we maximize our return on this potentially spectacular comet."

Deep Impact has executed close flybys of two comets -- Tempel 1 and Hartley 2 -- and performed scientific observations on two more -- comet Garradd and now ISON. The ISON imaging campaign is expected to yield infrared data, and light curves (which are used in defining the comet's rotation rate) in addition to visible-light images. A movie of comet ISON was generated from initial data acquired during this campaign. Preliminary results indicate that although the comet is still in the outer solar system, more than 474 million miles (763 million kilometers) from the sun, it is already active. As of Jan. 18, the tail extending from ISON's nucleus was already more than 40,000 miles (64,400 kilometers) long.

Long-period comets like ISON are thought to arrive from the solar system's Oort cloud, a giant spherical cloud of icy bodies surrounding our solar system so far away its outer edge is about a third of the way to the nearest star (other than our sun). Every once in a while, one of these loose conglomerations of ice, rock, dust and organic compounds is disturbed out of its established orbit in the Oort cloud by a passing star or the combined gravitational effects of the stars in the Milky Way galaxy. With these gravitational nudges, so begins a comet's eons-long, arching plunge toward the inner solar system.

ISON was discovered on Sept. 21, 2012, by two Russian astronomers using the International Scientific Optical Network's 16-inch (40-centimeter) telescope near Kislovodsk. NASA's Near-Earth Object Program Office, based at JPL, has plotted its orbit and determined that the comet is more than likely making it first-ever sweep through the inner solar system. Having not come this way before means the comet's pristine surface has a higher probability of being laden with volatile material just spoiling for some of the sun's energy to heat it up and help it escape. With the exodus of these clean ices could come a boatload of dust, held in check since the beginnings of our solar system. This released gas and dust is what is seen on Earth as comprising a comet's atmosphere (coma) and tail.

ISON will not be a threat to Earth -- getting no closer to Earth than about 40 million miles on Dec. 26, 2013. But stargazers will have an opportunity to view the comet's head and tail before and after its closest approach to the sun -- if the comet doesn't fade early or break up before reaching the sun.

Launched in January 2005, NASA's Deep Impact spacecraft traveled about 268 million miles (431 million kilometers) to the vicinity of comet Tempel 1. On July 3, 2005, the spacecraft deployed an impactor that was essentially "run over" by the nucleus of Tempel 1 on July 4. Sixteen days after comet encounter, the Deep Impact team placed the spacecraft on a trajectory to fly past Earth in late December 2007. This extended mission of the Deep Impact spacecraft culminated in the successful flyby of comet Hartley 2 on Nov. 4, 2010. In January of 2012, the spacecraft performed, from a distance, an imaging campaign on comet C/2009 P1 (Garradd).

To date, Deep Impact has traveled about 4.39 billion miles (7.06 billion kilometers) in space.

JPL, a division of the California Institute of Technology in Pasadena, manages the Deep Impact mission for NASA's Science Mission Directorate, Washington. The mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

More From ScienceDaily

More Space & Time News

Featured Research

Mar. 31, 2015 — Astronomers have conducted observations of the massive-star forming region IRAS 16547-4247. The observation results shows the presence of multiple, or at least two, gas outflows from a protostar, ... full story

Mar. 30, 2015 — Observations made with two space observatories, Herschel and Planck, reveal glimpses into how today's galaxies came to be. Using one-of-a-kind instrumentation, astronomers were able to study large ... full story

Mar. 30, 2015 — Stars form when gravity pulls together material within giant clouds of gas and dust. But gravity isn't the only force at work. Both turbulence and magnetic fields battle gravity, either by stirring ... full story

Mar. 30, 2015 — Scientists have long puzzled over the planet Mercury's excessively dark surface. New research suggests that carbon from passing comets could be the planet's mystery darkening ... full story

Mar. 30, 2015 — Luke Skywalker's home in "Star Wars" is the desert planet Tatooine, with twin sunsets because it orbits two stars. So far, only uninhabitable gas-giant planets have been identified circling such ... full story

Mar. 26, 2015 — Astronomers have studied how dark matter in clusters of galaxies behaves when the clusters collide. The results show that dark matter interacts with itself even less than previously thought, and ... full story

Mar. 26, 2015 — The best observations so far of the dusty gas cloud G2 confirm that it made its closest approach to the supermassive black hole at the centre of the Milky Way in May 2014 and has survived the ... full story

Mar. 25, 2015 — Researchers have completed a new analysis of an ancient Martian lake system in Jezero Crater, near the planet's equator. The study finds that the onslaught of water that filled the crater was one of ... full story

Mar. 25, 2015 — The precise measurement of Saturn's rotation has presented a great challenge to scientists, as different parts of this sweltering ball of hydrogen and helium rotate at different speeds whereas its ... full story

Related Stories

Dec. 2, 2013 — After several days of continued observations, scientists continue to work to determine and to understand the fate of Comet ISON: There's no doubt that the comet shrank in size considerably as it ... full story

Dec. 1, 2013 — Continuing a history of surprising behavior, material from Comet ISON appeared on the other side of the sun on the evening on Nov. 28, 2013, despite not having been seen in observations during its ... full story

Nov. 27, 2013 — As Comet ISON heads toward its closest approach to the sun -- known as perihelion -- on Nov. 28, 2013, scientists have been watching through many observatories to see if the comet has already broken ... full story

Nov. 22, 2013 — It began in the Oort cloud, almost a light year away. It has traveled for over a million years. It has almost reached the star that has pulled it steadily forward for so long. On Thanksgiving Day, ... full story

Apr. 23, 2013 — When the Hubble picture of ISON was taken on April 10, the comet was slightly closer than Jupiter's orbit at a distance of 386 million miles from the Sun. Hubble photographed a jet blasting dust ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.